20+ Glass Gem Corn Seeds, Ornamental Corn

Glass Gem Corn Seeds, Ornamental Corn (Zea mays) produce tall, vigorous stalks bearing spectacular ears filled with glossy, translucent kernels in shades of blue, purple, pink, red, green, yellow, orange, and pearl white. Every ear develops a unique combination of jewel-like colors, making this open-pollinated heirloom variety especially popular for autumn displays, crafts, table decorations, and seed-saving projects. Glass Gem is a flint or popcorn-type corn rather than sweet corn. Once fully dried, its edible kernels can be popped or ground into colorful cornmeal, although the popped corn will not retain the original rainbow colors. Plants generally grow approximately 6–9 feet tall and produce ears around 3–8 inches long.

Planting Season

Best planted in: Late Spring & Early Summer (Warm-Season Crop)

Sow directly outdoors after all danger of frost has passed and the soil temperature has reached at least 60°F (16°C). This long-season corn should be planted approximately 110–120 days before the first expected autumn frost so the ears have enough time to mature and dry properly.

How to Grow Glass Gem Corn Seeds

Direct sow the seeds outdoors because corn generally performs best when its roots are not disturbed by transplanting.

Choose a location receiving at least 6–8 hours of direct sunlight each day.

Grow in fertile, loose, well-drained soil enriched with compost or well-aged organic matter.

Sow seeds 1–2 inches deep. Plant closer to 1 inch deep in heavy soil and up to 2 inches deep in light, sandy soil.

Space seeds approximately 8–12 inches apart, with rows spaced 30–36 inches apart.

Plant in a block of at least four short rows rather than one long row. Corn is wind-pollinated, and block planting helps pollen reach the silks and produces fuller ears with fewer missing kernels.

Keep the soil consistently moist but not waterlogged during germination.

Maintain soil temperatures between approximately 60–90°F (16–32°C), with warmer soil encouraging faster germination.

Seeds typically germinate within 7–14 days under suitable conditions.

Thin seedlings to the strongest plant every 8–12 inches once they are several inches tall.

To preserve the distinctive colors and seed purity, separate Glass Gem from other corn varieties by approximately 300 feet when possible. Alternatively, stagger planting dates so different varieties do not release pollen at the same time.

How to Care for Glass Gem Corn Plants

Water deeply and consistently, providing at least 1 inch of water per week and more during hot or dry weather.

Consistent moisture is especially important during tasseling, silking, pollination, and ear development.

Water near the base of the stalks rather than frequently wetting the foliage.

Prepare the soil with compost before planting. Corn is a heavy feeder and performs best in nutrient-rich soil.

Apply a balanced fertilizer during early growth, then side-dress with a nitrogen-rich fertilizer when the plants are approximately knee-high and again as tassels begin to appear.

Mulch around established plants to retain moisture, regulate soil temperature, and suppress weeds.

Remove weeds carefully with shallow cultivation because corn roots grow close to the soil surface.

Glass Gem stalks are generally self-supporting, but planting in blocks and lightly mounding soil around the bases can improve stability in windy locations.

Allow the ears to mature completely on the stalks. Harvest when the husks have turned brown, dry, and papery and the kernels feel hard and glossy.

After harvesting, pull back or remove the husks and cure the ears in a warm, dry, well-ventilated location for several additional weeks before using them for decorations, storage, popping, or grinding.

Plants typically mature in approximately 105–120 days after sowing, depending on climate and growing conditions.

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